It’s probably purposeful obscurity, a marketing move for gold and jewelry.
Other alloys are described as ratios of elements.

At least I am starting to see carat fall out of use as a unit of weight, maybe from diamond manufacturing slowly making diamonds more of a commodity product.

It’ll probably take until we stop obsessing over gold before we can get rid of karat.

It’s 18 karat, not 24, so 75% gold and 25% probably silver.
That makes it a significantly harder alloy than pure gold.

biggest attack since Kyiv’s daring drone assault

Didn’t that literally just happen?
This has »“We haven’t seen each other since last year” in the first week of January« vibes.